#!/usr/bin/env bash
who
date

# testing variables, 等号两边无空格
days=10
guest="Katie"
echo "$/guest checked in $days days ago"
days=5
guest="Jessica"
echo "$guest checked in $days days ago"

# 基本运算，利用中括号
var1=100
var2=50
var3=45
var4=$[$var1 * ($var2 - $var3)]
var5=$[$var1 + $var3]
echo The final result is $var4
echo The final result is $var5

